ISSN : 1411-7703 e-ISSN : 2746-2625 BERKALA PENELITIAN TEKNOLOGI KULIT, SEPATU, DAN PRODUK KULIT POLITEKNIK ATK YOGYAKARTA, VOL. 21, EDISI 1 (2022) 8 Isolation of proteolytic bacteria from preserved skin in the warehouse of Politeknik ATK Yogyakarta Isolasi Bakteri Proteolitik dari Gudang Penyimpanan Kulit Politeknik ATK Yogyakarta Atiqa Rahmawati 1 , Ragil Yuliatmo 1* , R.L.M Satrio Ari Wibowo 1 , Dwi Wulandari 1 1 Department of Leather Processing Technology, Politeknik ATK Yogyakarta, 55188, Special District of Yogyakarta, Indonesia * Corresponding author :ragilyuliatmo@atk.ac.id Abstract Animal skin naturally contains various types of microorganisms. Microorganisms found in animal skins are able to reproduce quickly because animal skins contain a source of nutrients, high water content, pH and appropriate temperature in the tanning environment. Preserved skin in the Politeknik ATK Yogyakarta warehouse has accumulated due to the Covid-19 pandemic and it was unresolved problem. Utilization of preserved skin that has accumulated by isolating the bacteria found on the skin. One of the bacteria found on the skin is proteolytic bacteria, where proteolytic bacteria can produce protease enzymes. Protease enzymes have an important role in the eco-friendly tanning process. The purpose of this study was to isolate proteolytic bacteria that produce protease enzymes from piles of cow, goat and sheep skins that had been stored by the salting method for one year in the storage warehouse. The isolation process will be carried out on nutrient agar media and selective media, while the bacterial activity test in degrading protein is indicated by the presence of a halo zone. The results obtained from the study of isolation of proteolytic bacteria from the skin at the Politeknik ATK Yogyakarta Warehouse, showed that there was proteolytic activity which was indicated by the formation of a clear zone on the bacterial isolates taken from the salt preserved skin at the Politeknik ATK Yogyakarta Warehouse. The results of bacterial isolates that had a fairly wide clear zone were isolates A, C, D, E, and O. While isolate L did not show proteolytic activity. Optimal conditions for proteolytic propagation are at pH 7 and a maximum incubation time of 48 hours Keyword: Bacteria on the skin; Bacterial isolation; Proteolytic; protease. Intisari Kulit hewan secara alami mengandung berbagai macam tipe mikroorganisme. Mikroorganisme yang terdapat pada kulit hewan mampu berkembang biak dengan cepat dikarenakan pada kulit hewan terdapat sumber nutrisi, berkadar air tinggi, pH dan suhu yang sesuai di lingkungan penyamakan. Kulit awetan di gudang